Serial attached small computer system interface (SAS) is a communication protocol for enabling communication between computer devices. In the SAS protocol, SAS devices include initiator devices, target devices, and expander devices. Initiator devices are devices that can begin a SAS data transfer, while target devices are devices to which initiator devices can transfer data. Expander devices are devices that can facilitate data transfer between multiple initiator devices and multiple target devices. The SAS protocol utilizes a point-to-point bus topology. Therefore, if an initiator device is required to connect to multiple target devices, a direct connection can be established between the initiator device and each individual target device to facilitate each individual data transfer between the initiator device and each individual target device. A SAS switch is a SAS device that can include expander devices which can manage the connections and data transfer between multiple initiator devices and multiple target devices. A SAS fabric can include a network of initiator devices, target devices and expander devices.
Use of the same reference numbers in different figures indicates similar or identical elements.